Engine valve



' J. S. PETTY ENGIIE VALVE Filed Feb. 15.- 1922 2 Sheets-Sheet i JO/Z72 INVENTOR ATTORNEY WITNESS:

NOV. 1, 19270 I J. S. FEET! ENGINE VALVE Filed Feb. 15, 1922 2 Sheets-Sheet 2 5 l if 35- I ATTO R EY Patented Nov. 1, 1927.

T OFICE.

JOHN S. PET'IY, 0F BOWLING GREEN, KENTUCKY.

ENGINE VALVE.

Application filed February 15, 1922. Serial No. 536,734.

This invention relates to improvements in balanced valves for controlling steam to and from the cylinder of an engine, the invention being especially adapted for use upon steam locomotives.

An object of the invention is the provision of a steam balanced valve wherein live steam on its way to the cylinder port entirely surrounds the sides of the valve member, so that pressure all around said member is equal and frictional contact due to uneven pressure of the steam against only one side of the valve member is eliminatech while the exhaust steam is directed through the steam chest to each end of the valve chamber to prevent objectionable pounding or knocking, the result being practically a steam supported or floating valve.

Another object of the invention is the provision of means for ai'ltomatically releasing the valve member from the valve stem rod, so that when the locomotive is drifting, both cylinder ports will be opened at the same time, permitting steam or operating fllllCliO pass from one cylinder member to the other through by-pass exhaust passages and also through the valve member and prevent'cold air from entering the cylinder and causing the formation of carbon.

With the above and other objects in View, the invention further includes the following novel features and details of construction, to be hereinafter more fully described, illustrated in the accompanyingdrawings and pointed out in the appended claims.

In the drawings Figure 1 is a vertical sectional view through the cylinder of a steam engine with the improved valve applied thereto the valve being in the position occupied when steam cut ofi.

Figure is a similar view showing the valve at the full limit of its stroke.

Figure 3 is a horizontal sectional view showing the position of the valve when working on a short stroke.

Figure 4:18 a section on the line 1% of Figure 3.

Figure 5 is a similar view on the line 55 of Figure 3.

Figure 6 is a like view Figure 3.

Figure 7 is an enlarged longitudinal sectional view through the valve member show on the line 66 of parts when subjected Figure 10 is a fragmentary plan view of a portion of the bushing of the valve chamber. Referring in detail to the drawings, wherein like characters of reference denote corresponding parts, the reference character 11 indicates the cylinder of a steam engine equipped with the usual cylinder heads 12, piston head 13 vided with the usual cylinder ports 15.

Secured to the cylinder 11- is a steam chest orvvalve casing 16, which is provided with ports 1'7, :whereby communication is estab lishcd with the cylinder port 15, the ports 17 providing for the passz'ige of live steam from the valve chamber 18, steam being admitted to this chamber through an inlet port 19.

The steam chest or valve casing is provided with an exhaust port 20 and in the present invention, this exhaust port is in communication with each end of the valve chamber 18 through the medium of by-pass passages 21, located upon opposite sides of the steam chest 16.

-The valve member which is indicated generally at 22 is of the reciprocatory piston type and is provided at each end with a head 23 having a peripheral groove for-the reception of a packing ring 24. These pack ing rings 241 operate. against a bushing 25 located at each end of the valve chamber 18,

while surrounding these bushings and comand piston rod 14 and promunicating with the ports 17 are annular passages or chambers 26. The bushings 25 are provided with spaced openings 27 which communicate with the passages or chambers 26 and these openings are preferably ar- -anged at an incline as shown in Figure 10 of the drawings so as toprovide proper bearing for the heads 23 of the valve member 18 during its movement. 7

As thus far described, steam entering the chamber 18 through the port 19 will pass into the cylinder 11 through one of the cylinder ports 15 and during its passage will pass through one of the ports 17 and around the annular chamberor passage 26. hen the valve member 22 is working on a her 22. This member short stroke as illustrated in Figure 3, this steam from the chamber or passage 26 will maintain an equal pressure all around the valve head to the right shown in this figure so that pressure of steam against one side of the valve only will not occur and trictional engagement of the valve member with the bushing will be prevented, so that no dragging action of the valve will occur. As the exhaust steam passes out through the opposite cylinder port, the said exhaust steam will travel through the exhaust bypass passages on its way to port 20 and will thus enter each end of the valve chamber upon opposite ends of the valve member so as'to practically equalize the pressure of the exhaust steam in each end of the valve chamber.

Another novel feature of the invention resides in the construction of the valve memincludes the heads 23 and inner and outer sleeves 28 and 29 respectively, each of which has one end con- 'nected to one of the heads 23. The outer sleeve 29 has a threadedengagement with a ring or annulus 30 which surrounds the inner sleeve '28, while the inner sleeve has a threaded engagement with a ring or annulus 31 which is located within the outer sleeve 29. An additional split ring or annulus 32 is located within the outer sleeve 29 and surrounds the inner sleeve 28 and is provided with a beveled face 33 for engagement with a similarly beveled face provided on the ring or annulus 31' so as to provide a steam tight joint. Surrounding the inner sleeve 28 is a spring 34. and this spring acts to contract the valve member so as to reduce is limited by collars 35 its length, as shown in Figure 8 of the drawings. Expansion or relative movement of 'he-v'alve heads 23 in an opposite direction secured to the valve stem 36. This valve stem is connected to the "piston rod 1a through the usual valve gear.

I from the valve,

A port 37 is provided in the outer sleeve 29.

Normally, that is, when steam'is cut 0E the valve member will occupy the position shown in Figure 1 of the drawings so thatboth of the cylinder ports 15 will be opened. hen steam is admitted to the valve chamber, pressure will cause the valve heads 23 to separate, their move- "ment in this direction being limited by the hen steam is out off from stop collars 35.

the locomotive 1s drifting,

the valve and the valve heads will be contracted or moved toward one anotherby the action' of the 3 spring 34, the stop collars 35 accurately positioning the valve member between the cylinder ports 15 due to reciprocatory action of the valve stem rod 36. whereupon the said rod will move through the valve member and the latter will remain in this position.

This positioning of the valve member 22 would occur without the use of the spring 3 1 in reserved to make as Contact of one of the collars 35 with one of the valve heads will move the said valve head inward to the limit of movement oi the said collar, while the other collar acting in an opposite direction against the other valve head 23 would move the said valve head likewise inward, the spring 3d merely aiding in this performance or this operation. \Vhcn in this'position, the piston head 13 may operate in the usual manner, the operating fluid compressedat one end of the cylinder passing outward through the cylinder and being drawn in through the opposite cylinder port at the opposite end of the cylinder through he by-pass passages 21, so that cold air will;

be prevented from entering the cylinder and causing a carbonization of the lubricant therein. As the openings in the valve heads through which the valve stem rod passes are of greater diameter than the diameter of the said stem, the operating fluid will also be permitted to pass through'this valve memher.

The invention is susceptible of various changes in its form, proportions and minor details of construction and the right is heresuch changes as properly fall within the scope of the appended claims.

Having described the invention what is claimed is 1. The combination with a valve chamber having spaced inlet and outlet ports, of a valve member including spaced heads, telescopically arranged relatively movable sleeves secured to the heads, a spring between said sleeves for actuating said heads to move the latter relatively to each other in one direction and means for limiting movement of the heads in an opposite direction.

2. The combination with a valve chamber having inlet and outlet ports and a centrally located longitudinally movable valve rod extending through the chamber, of a valve member including spaced heads having openings therein for the passage of the rod, telescopically arranged relatively movable sleeves secured to the heads and surrounding said rod, a spring between said sleeves for actuating said heads to move the heads inward relatively to each other and'means carried by the rod for-engagement by the heads for limiting outward movement of the heads.

3. The combination with a valve chamber having inlet and outlet ports and a centrally located longitudinally movable valve rod extending therethrouglnbf a valve member including spaced heads having openings therein for the passage of the rod, a sleeve connected to each of the heads, said sleeves being slidable one within the other, means whereby fluid may be admitted to the charm her to move the heads outwardly, means for limiting such movement, and an expansible spring between said-sleeves for moving the heads inward.

4. The combination with a valve chamber having inlet and outlet ports and a centrally located longitudinally movable valve rod extending theretln'ongh, of a valve'memher comprising inner and outer relatively movable sleeves, a valve head secured to the outer end of each sleeve, spacing rings secured to the inner ends of the sleeves whereby the latter may be slidingly connected, means whereby pressure may be admitted to the chamber to move the heads out-ward relatively to each other, spaced stops secured to the rod for limiting outward movement of the heads and a spring located between the sleeves and bearing against the spacing rings for yieldingly forcing the heads inward.

V 5. The combination with a valve chamber having inlet and outlet ports therein and a valve rod movably mounted therethrough, movable heads mounted on said rod, an outer sleeve rigidly connected to one of said heads, an inner sleeve rigidly connected to the op posite head, spacing rings at opposite ends of said sleeves and a spring bearing against said rings to move the heads relatively to each other.

In testimony whereof I affix my signature.

JOHN S. PETTY. 

